The Best Way to Keep Weight Off

Losing weight is only half the battle — for many people, the bigger challenge is keeping the weight off over the long term. But is there a secret formula for success? To find out, Live Science interviewed experts and conducted a weekslong search for the best studies on the topic of keeping weight off. We combed through the evidence, and boiled it down to provide simple, science-based tips for how to maintain a slimmer, healthier self.

After a diet, it's common for people to regain some or all of the weight they lost — sometimes this is called "yo-yo dieting." A 1999 study estimated that just 20 percent of overweight or obese Americans are successful at losing at least 10 percent of their body weight, and keeping this weight off for at least a year. In fact, even people who are eventually successful at maintaining weight loss often go through several failed attempts first, other research shows. Researchers who followed more than 700 people who successfully lost at least 30 lbs. (13.6 kg) and kept it off for a year or more found that 91 percent reported they had previously made unsuccessful weight-loss attempts before they were finally able to keep the weight off.

"The challenge is that your body is very able to adapt to change," said Dr. Bruce Lee, director of the Global Obesity Prevention Center at Johns Hopkins Bloomberg School of Public Health in Baltimore. "If you have been at a certain weight for a while, then the body tends to try to maintain that weight," Lee told Live Science.

But there is good news: Studies have revealed that people who are successful in keeping weight off share common habits. Although people tend to lose weight in lots of different ways, "what they're doing to maintain weight loss is a little more consistent," said J. Graham Thomas, an assistant professor of psychiatry and human behavior at the Weight Control & Diabetes Research Center of The Miriam Hospital in Providence, Rhode Island.

We describe in detail below the exercise and dietary habits most commonly seen in people who successfully keep weight off, and the science behind them. 

Why is it so hard to keep weight off?

The truth is that, if you want to keep weight off, the cards are stacked against you: Your brain and your body are hard-wired to regain lost weight. This, combined with the abundance of high-calorie foods available today, makes it all too easy to put the pounds back on, experts told Live Science. After you've lost weight, your metabolism slows down, so you burn fewer calories than would be expected, even when you're at rest. "Your body goes from being like a truck, burning a lot of fuel, to being more like a Prius, burning less gas to go the same distance, when you've lost weight," Thomas said. This happens because your brain senses your fat stores are low, and sends signals to the muscles to become more efficient. 

In fact, people who lose 10 percent of their body weight actually need to eat 20 percent fewer calories once they reach their new weight, compared with other people with the same weight, to maintain their weight loss, said Dr. Michael Rosenbaum, a professor of pediatrics and medicine at Columbia University Medical Center in New York, who has studied weight-loss maintenance. For example, a person who weighed 200 lbs (90.7 kg), and then lost 20 lbs (9 kg), so that his or her weight was now 180 lbs (81.6 kg), would require about 300 to 400 fewer calories per day than a person who naturally weighed 180 lbs. "It's a disproportionately lower number of calories to stay right where you are," he said. [Here's Why It's So Hard to Maintain Weight Loss]

On top of this metabolic slowdown, multiple systems in the body undergo changes that affect our desire to eat. For example, after weight loss, your appetite increases, you have to eat more to feel satiated and you may increase your preference for higher calorie foods, according to a 2015 review paper from a government-backed panel of weight-loss experts. Areas of the brain involved in the ability to resist eating are also less active, Rosenbaum said.

"You've created the best possible scenario to regain the weight you've lost," Rosenbaum said.

Physiological factors that keep weight on and drive a person to overconsume high-calorie foods would have been useful back when humans were hunter-gathers, and had to cope with periods of famine. But these adaptations are problematic today in developed countries, where high-calorie foods are so readily available. "Our brains and our bodies and our genetics are not well suited to our current environment," Thomas said.

Not getting enough sleep may also interfere with maintaining weight loss. A 2012 study found that sleep-deprived people show more activity in the brain's reward center when looking at pictures of unhealthy foods, and are more interested in these foods, than people who are well rested. And a study published  in 2013 found that people who spent five nights in a sleep lab, sleeping just five hours a night, gained nearly 2 lbs (0.9 kg) over a two-week period, because they were overeating.

Finally, although many people can resist high-calorie foods for a limited period, it's often hard to keep this up over the long term, Thomas said. This may be because, when a person is losing weight, they experience the reward of seeing the pounds drop off, but when they're simply maintaining weight, this reward goes away, according to the 2015 review paper.

Beating the odds

But despite these obstacles, there are some people who've managed to beat the odds, and keep weight off for years. To better understand how these dieters kept their weight off, in 1994 researchers at Brown Medical School and the University of Colorado launched the National Weight Control Registry, which tracks the habits of individuals with successful weight-loss maintenance. It's now the largest study of its kind, with more than 10,000 people. Because of the large size and long duration of the study, much of what we know about successful weight loss comes from this registry.

To be included in the study, adults need to have lost at least 30 lbs (13.6 kg), and kept it off for at least a year. But the average person in the study has lost 66 pounds (30 kg), and kept it off for 5.5 years. Participants must also provide verification of their weight loss, such as medical records. Every year, participants answer questions about their weight, diet and physical activity, as well as their strategies for maintaining weight loss. More than two dozen scientific papers have been published from the registry. Some of the most important findings from the registry are highlighted below.

How much exercise do you need?

When you're trying to lose weight, your diet is the most important factor, but when you're trying to maintain weight loss, exercise becomes the most important factor, said Dr. Jacinda Nicklas, a physician and weight-loss researcher at the University of Colorado Denver's School of Medicine.

Studies involving data from the National Weight Control Registry have shown that people who successfully keep weight off exercise more than the average person; for example, they walk for 60 to 75 minutes per day. In line with these findings, Nicklas recommends 60 to 70 minutes of moderate-intensity aerobic exercise (like walking) per day, six days a week. If you do more vigorous activity, such as running, then your exercise routine doesn't need to be quite as long: about 35 to 45 minutes a day is enough, she said.

Because this amount of activity can seem daunting, Nicklas recommends that people start increasing their physical activity levels during the weight-loss phase, so that by the time they get to the maintenance phase, they are ready for the high levels of activity needed to maintain weight loss The researchers at the National Weight Control Registry note that, although 60 minutes per day is the average amount of exercise for the registry participants, some people engage in less activity and still keep their weight off. But Thomas recommends at least 200 minutes a week (or about 40 minutes a day, five days a week) to maintain weight loss. [2016 Best Pedometers]

One reason exercise is important for keeping weight off is that studies suggest it can prevent the metabolic slowdown that happens with weight loss, so the body burns more calories even in a resting state than it would if the person wasn't exercising regularly, Thomas said. Higher amounts of physical activity also mean you don't have to be as strict about your diet as you were when trying to shed pounds. "In order to counterbalance being more free with your diet, you have to have the exercise to have a buffer to prevent weight gain," Nicklas said. But this doesn't mean you can eat whatever you want — you still have to be careful with your diet so that you don't consume more calories than you burn. [The Great Calorie Debate: Does Weight Loss Come Down to a Simple Equation?]

Are certain foods better for keeping weight off?

There's no "magic" diet for maintaining weight loss, Nicklas said, but studies of the National Weight Control Registry do find some consistent eating habits that may be helpful. Overall, people in the registry tend to consume low-calorie, low-fat foods. On average, they eat about 1,380 calories per day, with 29 percent of their calories coming from fat. (Men in the registry eat about 420 calories more per day than women, on average.)

Registry participants are more likely to say they eat "modified foods" that contain less fat and sugar, compared with people who've always been a healthy weight.

For example:

• About 60 percent eat low-fat dairy, compared with 49 percent of people who have always been a normal weight.
• Registry participants consume three times more servings of artificially sweetened soft drinks, like diet soda, compared with people who have always been a normal weight.
• About 55 percent said they ate low-calorie dressings and sauces, compared with 44 percent of people who have always been a normal weight.

Eating these "modified foods" may help people consume a satisfying volume of food without eating excessive calories and fat, the researchers said. What's more, participants in the National Weight Control Registry have less variety in their diet — they come up with a healthy diet that works for them, and don't stray from it much. "These folks are selecting a more limited diet of 'safe foods' that they eat over and over again," Thomas said. [4 Calorie-Cutting Tips That Won't Leave You Hungry]

This "boring" type of eating may work to help sustain weight loss because it creates an environment that's essentially the opposite of one that promotes weight gain — where there are a variety of tasty, high-calorie foods. "Just by limiting the variety of foods that we allow ourselves to consume, we reduce the likelihood of unintentionally overeating foods with an unknown number of calories, fat grams, etc.," Thomas said. In addition, when people eat the same foods over and over, they become less excited by the foods, and so eat less of them, he said.

More than three-quarters of registry participants also say they eat breakfast every day. This fits with studies showing that people who skip breakfast tend to weigh more than people who eat a healthy morning meal, according to the National Institutes of Health. It may be that people who skip meals end up feeling hungrier later in the day, and this causes them to overeat. "One theory is that eating breakfast in the morning helps reduce the likelihood that hunger becomes overwhelming and uncontrollable over the course of the day," Thomas said. In addition to breakfast, registry participants eat other regular meals — on average, participants eat about five times a day.

In addition, they go out to eat less frequently than the typical American. On average, registry participants eat less than one fast-food meal per week, on average, compared with two to three fast-food meals per week for the typical American, studies have found.

Many experts emphasize that a successful diet is one that can be maintained long term. This means you should not completely deprive yourself of your favorite foods, or starve yourself all day. You can eat foods you like in moderation, but this should be balanced with fruits, vegetables, whole grains, leaner meats, low-fat dairy products and water. "This balance can aid fullness [and] reduce cravings ... while keeping caloric intake lower," said Mary Ellen DiPaola, a registered dietitian at the University of California, San Francisco Medical Center.

Michaela Kiernan, a senior research scientist at Stanford University School of Medicine, recommends trying to find some healthful, low-calorie foods that you think taste as good as the high-calorie foods you used to eat. This will probably mean that you'll need to try lots of new foods in order to find wholesome "replacements" that work for you, Kiernan said. And when you do indulge in your favorite, high-calorie foods, you should eat them mindfully — savor and relish them, Kiernan said. Mindful eating may help you feel satisfied without consuming too much.

DiPaola also suggests planning meals to avoid overeating, including what it is you wish to eat, when and where you will buy the food, how it will be prepared, how much you will eat and when it will be eaten.

What other habits are important?

Another important habit for maintaining weight loss is self-monitoring, which means keeping close tabs on your weight and eating habits. Studies have found that people in the National Weight Control Registry weigh themselves at least once a week, and over half of them track their daily food intake. Monitoring weight is important so that people know right away when the pounds are starting to creep back. "It's easier to catch and reverse a weight gain of a few pounds than it is to catch and reverse a weight gain of 10 to 15 lbs (4.5 to 6.8 kg)," Thomas said.

Some early studies suggest that technologies, like smartphone apps, can help with self-monitoring, or may even improve self-monitoring over traditional paper diaries. For example, a small 2014 study found that people tracked their diet more consistently with an app than with pen and paper. This may be because apps make tracking easier, and can be more engaging, Thomas said. [The Best Calorie-Counter Apps]

Kiernan said that people can start some of the habits that will help them maintain their weight loss even before they actually lose weight. For example, sherecommends that you weigh yourself daily to see how your body weight fluctuates even when you aren't on a diet. You can then come up with a 5-pound range for the upper and lower limits to your current weight. When your weight gets close to the upper limit of your range, you can make small changes to keep yourself at your current weight, like eating 20 percent less at meals for a few days, or taking an extra walk, Kiernan said. Once you've familiarized yourself with these strategies, you can use them to help maintain weight after weight loss.

In a 2012 study, Kiernan found that women who mastered these weight-maintenance strategies before they embarked on a weight-loss program were better able to keep the pounds off later. A year after the weight-loss program ended, women who learned the maintenance skills first regained only 3 lbs (1.3 kg), while women who lost weight first regained 7 lbs (3.2 kg). Kiernan also recommends anticipating life disruptions — like vacations — and making small tweaks in advance. For example, you can work to get to the bottom of your weight range before going on vacation.

Reducing "screen time" may also help with weight-loss maintenance. A 2006 study of 1,400 members of the National Weight Control Registry found that 62 percent said they watched 10 or fewer hours of TV per week. At the time the study was conducted, the typical American spent, on average, 28 hours per week watching TV.

 And support from family or friends may also help people stay on the right track to maintain their weight. A 1999 study of 166 people who had participated in a weight-loss program found that 66 percent of people who brought friends with them to the program sessions maintained their full weight loss six months after the program ended, compared with 24 percent of those who attended the sessions alone.

But certain kinds of support may be better than others. Researchers in Greece looked at differences in support between 289 people who were able to maintain their weight loss for over a year, and 122 people who regained their weight. The study, detailed online Jan. 22, 2016, in the Journal of Behavioral Medicine, found that people who regained weight actually received more support overall from their social network, but it was often in the form of reminders of what they should and shouldn't do. In contrast, people who maintained their weight received more compliments about their weight, and their friends were more likely to actively help them with their maintenance goal, for example, byeating healthful foods with them. [The Surprising Things You Shouldn’t Say to Someone Who’s Lost Weight]  

So although the challenge of keeping weight off can sometimes seem impossible, there are a number of habits that seem to boost a person's chances of success. A healthful and consistent diet, lots of exercise and keen attention to your current weight and eating habits may help you win the struggle to keep weight off for good.

Follow Rachael Rettner @RachaelRettner. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.